package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //1.查出所有分类
        List<CategoryEntity> categoryEntities = baseMapper.selectList(null);

        //2.组装父子
        List<CategoryEntity> rootCategoryList = categoryEntities.stream().filter(item -> item.getParentCid() == 0)
                .map((menu) ->{
                    menu.setChildrenCategory(getChildrens(menu,categoryEntities));
                    return menu;
                }).sorted(Comparator.comparingInt(menu -> ((menu.getSort() == null) ? 0 : menu.getSort())))
                .collect(Collectors.toList());

        return rootCategoryList;

    }

    //获取子类的孩子
    public List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> categoryEntityList){

        List<CategoryEntity> collect = categoryEntityList.stream()
                .filter(item -> {
                    return item.getParentCid() == root.getCatId();
                })
                .map(categoryEntity -> {
                    categoryEntity.setChildrenCategory(getChildrens(categoryEntity, categoryEntityList));
                    return categoryEntity;
                })
                .sorted(Comparator.comparingInt(menu -> ((menu.getSort() == null) ? 0 : menu.getSort())))
                .collect(Collectors.toList());

        return collect;
    }

}